An article from Belgium shows that lifting heavy weights to failure makes older people stronger, even though all people lose strength with aging (Experimental Gerontology, August 13, 2013).

Why You Weaken with Aging
A major penalty of aging is that you lose muscle and become weaker no matter what you do. Every muscle in your body is made up of thousands of muscle fibers just as a rope is made up of many threads. Every muscle fiber is innervated by a single nerve fiber. With aging you lose nerves. When you lose a nerve fiber attached to a muscle fiber, that muscle fiber is lost also. So a 20 year old person may have 800,000 muscle fibers in the vastus lateralis muscle in the front of his upper leg. At age 60, that muscle has only 250,000 fibers.

Make Muscle Fibers Larger
You cannot stop this loss of muscle fibers completely, but you certainly can enlarge each muscle fiber and slow down your loss of strength by exercising muscles against progressive resistance: lifting weights or using special strength-training machines. The key to becoming stronger is to exercise against resistance until you can't do much more. (Watch out; you can injure yourself by lifting weights that are too heavy or by using poor technique).

Stress and Recover
To enlarge muscles, you have to exercise them against resistance forceful enough to damage the muscle fibers. You will know that you have done this because you will feel a burning in the stressed muscle during the later lifts and on the next day, your muscles will feel sore. Then you lift lighter weights for as many days as it takes for your muscles to heal. You can tell this has happened when the soreness goes away.

The Study
In this study, 56 older adults were randomly assigned to 12 weeks of leg press and leg extension training in three groups:
• HIGH: Two sets of 10-15 repetitions at 80 percent 1RM (1-Repetition Maximum, the heaviest weight that a person can lift once),
• LOW: One set of 80-100 repetitions at 20 percent of 1RM, or
• LOW PLUS: One set of 60 repetitions at 20 percent of 1RM, followed by one set of 10-20 repetitions at 40 percent of 1RM.

Results
1) The greatest gains in strength, measured by gains in 1RM (lifting a heavier weight one time) were in the HIGH and LOW PLUS groups. This shows that as long as you lift weights over and over again until you can't lift much more, and you allow time to recover, you will become stronger.
2) These gains in muscle strength showed up significantly after five weeks.
3) All groups grew larger muscles.
4) All groups generated more muscle force.
5) None of the groups were able to contract their muscles faster.

What Does this Mean for You?
This study shows that to enlarge muscles, you have to lift very heavy weights a few times in a row, or lighter weight many times in a row, to cause the muscle damage necessary for muscle growth. As you age, expect to become weaker and be more likely to fall and break your bones. You can markedly delay this loss of strength by lifting weights or using special strength training machines. You can become quite strong by:
• using 10 to 15 strength-training machines (for different muscle groups) three times a week,
• doing two or three sets of 10 repetitions on each machine,
• with weights that are 80 percent of the maximum weight you can lift once.
Always stop lifting immediately if you feel any pain, tearing or excessive burning.

How a 78-Year-Old Man and a 71-Year-Old Woman Are Getting Faster and Stronger

Many of you know that Diana and I race on a tandem bicycle three times a week. For the last couple of years we have gotten slower because we are getting older and becoming weaker. Three months ago we decided to try a new training method to see if we could get stronger and faster.

Our Previous Training
We had been using a standard stress-and-recover program used by many athletes in different sports. On Tuesdays, Thursdays and Saturdays we raced a 23 mile course as fast as we could. On the other four days, we recovered by riding 20 to 30 miles slowly at 10-12 miles per hour pace for two or three hours.

Our New Training to Become Stronger
Three months ago, we changed our program to:
• Racing the same 23 miles three times a week, with about 10 miles of warm up and cool down.
• On the other four days, warming up for 5-10 miles, then riding a series of all-out bursts at maximal effort for 30 seconds, followed with two-minute recovery periods.
We are usually able to do between 10 and 20 of these repeat 30-second intervals before our legs start to stiffen and feel fatigued. Then we cool down by riding slowly for about five miles. I know that riding very fast when muscles feel tight can cause injuries.

The Results
We still are not as fast as people who are up to 30 years younger than us, but we are riding faster than we were. The first month that we started doing intervals. we actually rode slower because we were tired and could not recover from the interval training of the previous day. In the second month we were riding as fast as we rode before we started the interval training. Now in the third month we can really feel the difference and are riding at least a mile per hour faster than we did before we started the interval training.

What We have Learned
We now know that slow miles are junk miles, even if you are doing the slow riding on days in which you are recovering from a previous hard day's workout. It doesn't matter how old you are. The key is to avoid injury by taking days off when your legs are stiff or sore. Never ride fast when you are hurting.

About the Author: Gabe Mirkin, MD

Sports medicine doctor, fitness guru and long-time radio host Gabe Mirkin, M.D., brings you news and tips for your healthful lifestyle. A practicing physician for more than 50 years and a radio talk show host for 25 years, Dr. Mirkin is a graduate of Harvard University and Baylor University College of Medicine. He is board-certified in four specialties: Sports Medicine, Allergy and Immunology, Pediatrics and Pediatric Immunology. The Dr. Mirkin Show, his call-in show on fitness and health, was syndicated in more than 120 cities.
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